Abstract

Obesity is a complex disease that has unfavorable impacts for all ethnic populations in worldwide. Genetics, environment and lifestyle are among aetiological factors of this disease. Genetic contribution associated with this disease is generally classified into 2 types: monogenic syndromes that display severe obesity, and the polygenic model of common obesity. Single-gene mutations can cause severe obesity resulting from alteration in central and peripheral appetite control mechanisms. Candidate gene and genome-wide association studies have led to the identification of nine loci associated with Mendelian forms of obesity and 58 loci contributing to polygenic obesity. These loci explain a small fraction of the heritability for obesity and many genes remain to be identified. The interaction of several polymorphisms and epigenetic modifications open a new research field for common obesity. As a result, still remains to be a mystery.

Key words: Genetic; Obesity; Body Mass Index; Gene.